Ignition system.



D. B. HUGHES.

IGNITION SYSTEM.

APPLICATION FILED 111 11.21. 1910. RENEWED sEPT.25. 1914.

1,138,569, Patented 1111 4, 1915.

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new 3. HUGHES, or CLEVELAND, OHIO, ASSIGNOR ho THE cI'rIzENs SAVINGS ANTRUST COMPANY, TRUSTEE, or CLEVELAND,

Y IGNITION SYSTEM.

Application filed April 27, 1910, Serial No. 557,889.

To all whom it may) concern:

Be it known that 1, Dow B. HUGHES, a

citizen of the United States, residing at terminals of the Spark plugconnected to that secondary and thereby reduces the re- Cleveland, inthe county of Cuyahoga and State of Ohio, have'inventeda certain new anduseful Improvement. in Ignition Sys-' tems, of which the following is afull, clear, and exact description. r

This invention relates to ignition Systems for internal combustionengines and is de- I signed as an improvement over an ignition systemdisclosed in my pendin application, filed. 553,111. I r p The Specificobjects of the present invention are to provide a system which is moresatisfactory in operation than the one disclosed in my pendingapplication referred to, and to simplify the construction of parts andthe number and arrangement of elec-' tric conductors and connections,and to reduce the cost of construction and installation.

In accordance with the present invention, I employ in connection with asuitable source of current, such as a magneto having a low Voltagewinding, suitable means for making and then breaking a short circuitabout the winding and connect the wind' ing to a distributer, thestationary segments or contacts of which are each connected to one ofthe spark. plugs to a disrufitive discharge coil and to a condenser.denser which is connected to one of the dis" tributer segments. isconnected to ground in series with the primary of the correspondingdisruptive discharge coil and in shunt to the corresponding spark plugand the secondary of the coil, the secondary and Spark plug being inseries.

The voltage of the generator is ordinarily insufficient to establisharcs across the terminals of the spark plugs, but with the arrangenientabove described, by temporarily sort-circuiting the armature winding,and then opening the same, the condenser which is in circuit with thesegment which happens to be connected to the armature winding throughthe movable member of the distributer is charged and discharged withgreat rapidity, setting up in the primary which is in series with thatcondenser, a high frequency current of high voltage but of extremelylow. amperage. The high fre quency current induces a. high frequencySpecification of Letters Patent.

April 2nd, I910, erial No..

ach conmarized as consisting in certain novel com- OHIO, A CORPORATIONOF OHIO.

- 'Patented May 4, 1915. Renewed September 25, 1914. Serial No.863,550."

-current in the corresponding -secondary, and

this induced high frequency current establishes an arc oflow heat valueacross'the sistance of the; air gap to an extent such that this are oflow heat value is followed up by an arc of 'high heat value produced bymagneto current, the voltage of the magneto to establish the are of highbeing sufficientheat value when the resistance of the air gap isreduced. The make and break device vertical position betweenthe "fieldpoles, and

the short circuiticontin'ues while the armature turns through'a suitableare or fr'ac-' the magnetic field'and building' upthe volt age so thatwhen the Short circuit is broken" and the high frequency current-isinduced in one of the spark plug circuits, the mag'- neto voltage willbe suflicient to establish"- the arc of high heat value. This are ofhigh heat value having been established be:

tween the electrodes, it continues for a con-.- siderable period and, infact, it continues until after the armature has. been moved through aconsiderable arc-and has passed beyond the position of highest Volta e.

The invention may be further brie y sumbinations and arrangements ofparts which will be described in thespecification and set forth in theappended claims.

Reference is had to the. accompanying sheet of drawings wherein Figurelis' a diagrammatic view of my improvedignition system for a fourcylinder engine, parts on the magneto armature shaft being projected atright angles so as. to show more clearly the operation and electric con-105 nections; Fig. 2 is a diagrammatic view of a portion of the fieldsand armature of the magneto and showing by dotted lines the' approximatepositions of-the armature when the armature winding is short circuited,and

tion of a-revolution and is sweeping intoshaft sections Hand 12 when theshort circuit is broken; Fig. 3 is a sine voltage curve showinggraphically the approximate comparative voltages when the winding isshort circuited-and opened.

Referring now to the figures of the drawing, and firstto Fig. 1, 10represents the magneto armature. which is su ported on and is providedwith a single'low voltage winding 13, one end of which is grounded at141, and the other end of which is connected to a collector ring 15which is supported on shaft .section 12, and is engaged by a brush 16.

At the opposite side of the generator from the ring 15 is a make andbreak device for short-circuiting and opening the short circuit of thearmature winding, this make and break device including a cam 17, a lever18. adapted tov be shifted by the cam, and a contact member 19 adaptedto be engaged by a corresponding contact member 20 on the lever, thiscontact member 19 being insulated from the frame work of the machine andbeing connectedby a conductor 21 to the brush 16. .The cam isconstructed in a manner such that at each half revolution thereof, thecontact members 19 and 20 are brought into engagement, and therefore, asthe cam and lever 18 are both grounded, the armature winding will betemporarily shortcircuited upon itself at each half revolution. The camand lever are shown Fig. 1, for the sake of clearness, as grounded byconductors, but in reality, by being mounted on the .grounded shaftsection 11, and the lever 18 Wlll be grounded by being pivotedupon aportion of the magnetoframe.

At 22 is shown a distributer or timing device which, for a four-cyclefour cylinder enginewill' be driven at one half magneto speed, and whichis provided with a mova le distributer arm 22, and stationary con factsor segments 22, the former being per manently connected by a conductor23 to the brush 16 which engages the collector ring 16, to which oneendof the armature winding is connected. The distributerarm is therefore at"all times electrically connected to the armature winding. Each ofthesesegments 22? is connected through the primary 24 of a disru tivedischarge coil. .24 and through a con enser 25 ,to ground, and is alsoconnected through the'secondary 24 'of the disruptive discharge coil vtooneof the spark plugs 26, one terminalof which is, of

'course," grounded. The primary of the coil and condenser are thereforein shunt to the secondary of the coil and thespark plug. The condensers25 have small-capacity, as compared with the vcondensers ordinarilyemployed in ignition systems, and in fact, I find that a condenserformed of substanr tially twenty square inchesof tin-foil arrangedinstrips, and separated by mica, pro:

the cam is grounded duces very good results, whereas the condenserordinarily employed in an ignition system containsjhundreds of squareinches of tin-foil. Also the disruptive discharge coils have very ,lowreactance, this condisegments of the distributer and consequently thedifferent spark plugs are successively connected to the armatureWinding, and by driving the distributer at one half the speed of themagneto and by providing a make and break device which short circuitsthe armature winding and then opens the same twice at each revolution ofthe magneto, as the distributer arm passes onto one of the segments, thearmature is short circuited and remains short-circuited for a fractionof a revolution of the armature, and is then opened. By opening theshort-circuit, the condenser 25, which is connected to that segment, ischarged and discharged, causing a high frequency current to be set up inthe primary 2& to which the condenser is connected, and this highfrequency current which is of high voltage but almost'negligibleamperage, induces a high frequency current in the correspondingsecondary 2 1". This induced high frequency current being of very highvoltage, although of low amperage, causes an arc of low heat value to beestablished across the corresponding spark lug. This are is ofinsufficient heat value to ignite the explosive mixture in the cylinderof an engine, but it reduces the resistance of the air gap of the sparkplug to an extent such that the magneto current at the generated voltagewill establish a flaming arc of, high heat value at the spark plug, thecurrent passing directly from the distributer arm to the segmentpreviously referred to, and into the plug through the secondary of theinduction coil. The condenser or high frequency circuit does notincludethe armature winding because of the make and. break device which,as before stated, is in shunt to. or. short circuits the armaturewinding. On the opening of the make, and break device the latter servesas 'a spark gap device across which the condenser is disruptivelydischarged. As the distributer arm passes to the next segment,

' the armature winding is again short circuit-' high frequency currentwhich induces in the denser for each spark plug, each of the stationarymembers of the distributer being connected to ground through the primaryof a disruptive discharge coil and condenser, and each being connectedto a spark plug through the secondary of the disruptive discharge coil.

5. In an ignition system, a magneto having an armature winding, one endof which through a condenser and a primary of a.

disruptive discharge coil, and being connected to ground. through thesecondary of the coil and through a spark plug, the

condenser and primary being 1n serles relation and being in shunt to thesecondary and the spark plug which are in series relation,

and means for making and breaking a short circult'about the armaturewinding.

6. In an ignition system, a generator, having a winding with meansfortemporarily and periodically short-circuiting the same, a pluralityof spark plugs, a distributer havlng its movable member connected to the"winding and having stationary contacts connec'ted to the difierentspark plugs, a'condenser connected to each of the distributer contacts,a plurality of disruptive discharge rent, a plurality of spark plugs,

coils, each having a primary connected to the condenser and a'secondaryconnected to a spark plug.

' 7 Inan ignition system, a source of cura disruptive discharge coil anda condenser for each spark plug, each condenser and a primary of onecoil being in series relationship, and a spark plug and the secondary ofthe same coil being in series relationship, and means including adistributerfor establishing connection between the source of current andthe different condensers, and also between the source of current andthedifierent spark plugs.

I 8;" In an ignition system, a source of current, a imake and breakdevice associated therewith,'a plurality of spark plugs, a distributerhaving its movable member connected to the source of current and havingstationary contacts connected to the different A 65 spark plugs, acondenser connected to each of the distributer contacts, a plurality ofdisruptive discharge coils, each having a primary connected to acondenser, and a secondary connected to a spark plug. In testimonywhereof, I hereunto afilx my signature in the presence of two witnesses.

DOW HUGHES.

Witnesses:

H. R. SULLIVAN, A. F. Kwrs.

